1. Field of the Invention
This patent relates to an improvement of a paper cutter.
2. Description of the Prior Art
Now, a conventional example of the paper cutter will be explained based on FIG. 20, in which a rail 3 is provided rotatably on a holding portion 2 of one end of the base 1, and on this rail 3 a slider 5 is applied. Further, the slider 5 is set not-separably from the rail 3 and both ends of the rail 3 are provided with stoppers. And, when paper cutting, the papers to be cut are put on the base 1, the rail 3 is inclined, an engaging pawl 6 mounted at the tip end of the rail 3 is hooked at the engaged portion 7 and the paper is fixed on the base by being clamped between the holding plate 4 on the below surface of the rail 3 and the upper surface of the base 1. And, by displacing the slider 5 laterally along the rail 3, a rotary blade applied to the slider 5 cuts the papers while rolling on the papers.
Further, the slider 5 is adapted to be provided in such a manner, as shown in FIG. 18, as the surface of the holder plate 504 is tightly in contact with the sliding surface 501 of the rotary blade 8 by inserting screw bars in through holes 504 pierced on the holder plate 505 while picking the knob 506 and fixing nuts 507 on the screw bars 503 projected from the through holes 505.
Further, in the patent laid-open publication No. Hei 8-229891, a rotary blade holder for preventing hands from touching directly the blade when replacing the rotary blade 8 is disclosed. Such situation is explained referring to FIG. 19, in the state where a cover 14 is opened the rotary blade 8 is inserted into a gap 15 with its one portion and held and fixed in the rotary blade holding surface 16, so that it is positioned within a U-letter recess portion 18 with its hexagonal hole 17 pierced at the center of the rotary blade 8. And, while a hexagonal shaft provided on the holder plate 504 shown in FIG. 18 is adapted to be coupled with the hexagonal hole 17 provided on the rotary blade 8, the rotary blade 8 is attracted to a magnet provided on the holder plate 504 due to pushing the holder plate 504 to the rotary blade 8.
Thus, by lifting up the rotary blade 8 until one portion of the rotary blade 8 is removed from the gap 15 while the rotary blade 8 being attracted to the holder plate 504 and picking up the knob 506, without touching the rotary blade 8 and while a new rotary blade being kept in the holder plate 504, the rotary blade 8 is adapted to be taken out from a holder body 9. And, as in FIG. 18, by mounting the holder plate 504 attracting the rotary blade 8 on the slider 5, the rotary blade 8 is adapted to be mounted on the slider 5 without touching the rotary blade 8.
Next, in a case where an old rotary blade 8 is accommodated in a holder 9, in FIG. 18, by removing the holder plate 504 due to picking up the knob 506 of the holder plate 504, the rotary blade 8 is removed from the slider 5 while being attracted by the magnet provided on the holder plate 504 and by picking up the knob 506 while attracting the rotary blade 8 to the holder plate 504 and inserting a portion of the rotary blade 8 in the gap 15 along the U-letter recessed portion 18, the rotary blade 8 is adapted to be accommodated in the holder 9.
In prior art shown in FIG. 17, a rail 10 is mounted on a normal paper support 109, which is formed substantially in a unit, and with this rail 10 is a slider 11 coupled. And this coupling of the slider 11 is carried out by engaging with T-letter of the rail 10 in section and on both side of the rail 10 stoppers 101 and 102 are provided to prevent the slider 11 from being removed from the rail 10. And, when cutting papers, by holding and fixing the papers to be set on a cutter sheet with the paper support 9 tightly with the left hand, it is carried out by making a cutter projected from a cutter blade (not rotary blade) from a cutter case 13 and displacing a cutter case 13 and displacing the slider 11. Further, the cutter blade is sunk in the cutter case 13 by releasing the holding of the projection 12 to avoid the hands from touching the cutter blade directly.
In any type of paper cutter mentioned above, since the slider is adapted not to be separated from the rail, the following problems to be improved are mentioned.
In the conventional art disclosed in FIG. 20, when replacing the rotary blade, since a new rotary blade accommodated in a holder is to be taken out in the state where the rotary blade is attracted to the holder plate 504 and this holder plate is to be mounted on the slider, the replacing process is difficult, and since a notice of taking care for avoiding the hands from being touched with the rotary blade, an improvement for handling such operation has to be carried out.
Further, since the slider 5 needs a lots of parts such as a holder plate 504 having a magnet, screw bar 503, nut 507 and a hexagonal shaft for pivoting the rotary blade 8, and since the magnet and the holder plate are different in material in addition they are not a single unit consisting of different materials, even though the holder plate body can be formed by a resin molding, the process of working the magnet and the one of connecting the magnet to the holder plate are separately carried out, and similarly even though the slider body can be formed by a resin molding, the screw bars are not single parts to be worked planted in separate processes, and that, since the hexagonal shaft has to be provided rotatably on the slider body, which cause the cutter to be highly costed to replace the rotary blade with the slider as a consuming part.
Further, in the prior art shown in FIG. 17, since the cutter blade itself can not be replaced and the slider can not remove from the rail, in the case where the cutter blade becomes dull, the paper cutter itself has to be abandoned.
Accordingly, the present invention is to provide a paper cutter in which, by forming the slider so as to make it as a single part consisting of a single material to become a low costed slider, and using a safety device to the slider itself, the slider is adapted to be replaceable together with the rotary blade to make it easy to replace the rotary blade and to enable to replace merely the slider made in a unit with the rotary blade, so that an economical loss can be minimized.